
import animation;

animation a;
unitsize(5cm);

path c1 = unitcircle;

draw(c1);
defaultpen(3);
real step  = 12;
real angle = 2*pi / step;
real x,y;
dot((0,0));

for (int i=0; i < step; ++i){
    save();
    x = sin(angle * i);
    y = cos(angle * i);
    draw((0,0)--(x,y),arrow=Arrow());
    a.add();
    restore();
}
dot();

a.movie(BBox(0.25cm),loops=10,delay=1000);
